Printing method and apparatus with wire printing elements

ABSTRACT

Apparatus and method for printing lines, dots, in patterns. A plurality of small size wires, filaments, etc. are suspended in free space in a frame and have printing media or substance applied thereto. The wires are brought into printing media or substance transfer relation with a substrate to transfer printing substance to the substrate in a pattern defined by the wires. If dots are to be printed on the substrate instead of lines, a transversely oriented second frame carrying a second set of suspended wires which wires are contacted by the first wires to transfer printing media only at the wire cross points and then the second set of suspended wires is brought to printing media transfer relation with respect to the substrate to thereby transfer printing media to the substrate in a pattern of dots having cross-sectional areas defined by the common area at the crossing of wires. Consult the specification for further features and details.

[ Dec. 30, 1975 United States Patent [1 1 Grier FOREIGN PATENTS OR APPLICATIONS [54] PRINTING METHOD AND APPARATUS WITH WIRE PRINTING ELEMENTS [75] Inventor:

550,617 l/1943 United Kingdom................... 117/93 Assignee:

[22] Filed:

Primary ExaminerJ. Reed Fisher Attorney, Agent, or Firm-D0nald Keith Wedding [57] ABSTRACT Apparatus and method for printing lines, dots, in pat- Related U.S. Application Data [63] Continuation of Ser. No. 796,797, Feb. 5, 1969,

abandoned.

terns. 'A plurality of small size wires, filaments, etc. are

suspended in free space in a frame and have printing media or substance applied thereto. The wires are [52] U.S. Cl. 101/298; 101/368; 101/426 [51] Int.

. B41F l/00 brought into printing media or substance transferrelation with a substrate to transfer printing substance to the substrate in a pattern defined by the wires. If dots are to be printed on the substrate instead of lines, a transversely oriented second frame carrying a second 0 2 6 0 2 Ma -v4 1 w. 9. 03 7 1mm 4 ,7 69 3 ,3 H47 339 3 ,3 .7 a 200 39 "a3 "3 1 3 a ,w 82 6 a m 1 rmz 1 d 1 e i F 1 8 5 1 set of suspended wires which wires are contacted by v the first wires to transfer printing media only at the References Cited wire cross points and then the second set of suspended UNITED STATES PATENTS wires is brought to printing media transfer relation a U mmC fi y O. -l .D H 6 g D. .l mm F tP e m wabm Rd mimw m m n. D SmC BA b dc 9 a 5 u a m eSef m h T11 l timfiwmc m wmmm 6 mmo m auulmu ...1 Sd S 880 m h S r .H w m 9 636 1 121 nm nm m I w mw m 11. m 0 nun l Reif m 5 m ma t .S n w: n u mf w wm hm h BKSSC 4920366 7456666 999990 9 1111111 5 2745 11 40044 3 0303,444 .J 6976953 46 6945 l4 6 9 O 2 2 222333 Lippard U.. Patsnt Dec. 30, 1975 Sheet 2 of2 3,929,070

INVENTOR JOHN D. GRIER BY 5;. 19462: g

ATTORNEYS PRINTING METHOD AND APPARATUS WITH WIRE PRINTING ELEMENTS RELATED INVENTION I This is a continuation of copending US. patent application Ser. No. 796,797, filed Feb. 5, 1969, now abandoned.

THE INVENTION bly, the, wires are round but they may be rectangular or I have any other cross-sectional shape and are typically under 2 mils in diameter or width, but larger sizes may be used. As used.herein one mil is defined as 0.001 inch. I

Printing Mediaf includes resistive and/or'non-resistive, non-conductive and/or conductive materials, such.

as phosphors, plastics, dielectric materials, resins, adhesives, electrostatic or non-electrostatic inks, etc. in the form or particles, paste, suspension, solution or slurry and is the substance which it is desired to apply in a pattern to a substrate. Line means a narrow, substantially straight, un-

curved length of printing media on a surface.

Dot"'means a very small spot or area of any desired geometric configuration, typically round or elliptical in perimeter, of printing media on a surface. I

Array" or pattern" means a systematic grouping or arrangement of wires or line or dot markings.

Substrate means a rigid or non-rigid member of any suitable shape to which it is desired to transfer or apply printing media, as for example a glass plate, plastic sheet, a second wire, etc. I, u

"Printing"'means the application or transfer of any printing media to a substrate to form an array or pattern.

Printing Media Transfer Relation meansthe bringj ing into the proximity of a substrate a set of wires carrying printing media so as to transfer such media from the wires to the substrate in an array or patterndefined by the wires and the printing media thereon.

While the invention will be described hereinafter in terms of specific application thereof to printing con ductive lines on rigid substrates, and/or'print'ing of dot patterns on such substrates, it will be understood that the invention is not to be so limited but encompasses printing arrays or patterns of lines and/or dots in general.

Objects of the invention include the rapid and inexpensive fabrication of narrow, uniform lines and/or dots having high resolution or definition a't precise locations on a substrate and improvement in resolution in the printing of such lines and/or dots wherein the variation in center to center distance between the lines and/o'rfdots is less than about 'inils and wherein highly uniform spacing of such lines and/or dots is achieved. A furtherobject of the invention is the utili zation of the basic technique described hereinbefore to print small dots of material where the dots may have a diameter of 2 mils or less and must be accurately registered and printed upon the substrate.

In the prior art lines and/or dots of uniform dimension and spacing have been printed by various methods including screen printing, photo etching techniques, vacuum deposition, etc. Such techniques while being widely used are typically slow, expensive or lack sufficient resolution. In accordance with this invention there is provided apparatus and method which results in relatively low cost, high resolution printing.

The broad practice of this invention comprises applying printing media to at least one suspended wire, and thereafter transferring printing media from the wire directly onto a substrate by bringing the printing media containing wire into printing transfer relation with respectto the substrate. The printing media may be transferred by adhesive and/or field force(s) such as capillary action, pressure contact, electrical field, magnetic field, etc. Preferably, the invention comprises low pressure and/or capillary transfer of printing media from the wires to the substrate.

Alternatively, in the embodiment comprising the printing of a dot, the invention comprises applying the printing media to at least one suspended wire and then bringing a transversely oriented second wire into media transfer relation with the first wire to effect transfer of printing media uniformly at the area of crossing between the wires. The printing media on the second wire is thereafter transferred to a substrate, e.g., as already noted hereinbefore.

Althoughthe foregoing has been described with reference to printing a single line or dot, the practice of the invention typically comprises printing a multiplicity of .lines and/or dots in an array or pattern. Such practice would, of course, comprise a plurality of suspended wires.

Also in a preferred embodiment of this invention, the suspended wire(s) is taut.

The above and other objects, advantages and features of the invention will become more apparent when considered in conjunction with the following description and the accompanying drawings wherein:

FIG. 1 is an isometric view of printing apparatus in accordance with the invention,

FIG. 2 is a partial side elevational of one end of the apparatus shown in FIG. 1,

FIG. 3 is a top diagrammatic view of printing apparatus for printing line or dot patterns in accordance with the invention,

FIG. 4 is a partial isometric view of the printing apparatus shown in FIG. 3,

"FIG. 5 is a cross-sectional elevational view of a substrate holder, and

FIGS. 6 and 7 are cross-sectional views included to illustrate examples of products printed in accordance with the invention.

With reference to FIGS. 1 and 2 of the drawings, wire printing assembly 9 includes a pair of rods 10 and 11 which are mounted in spaced apart assembly in a pair of frame members 13 and 14 with rod 10 being adjustable by means of tension adjusting screws 16 and 17 threadably engaged with laterally extending blocks 16B and 17B which slide in bifurcated ends 13E and 14E of frame members 13 and 14, for example. Rods l0 "and 11 have formed therein grooves or notches 10g and 11g, respectively. Wires or filaments 18 are wound around the rods 10 and 11, respectively, the spacing between grooves or notches 10g and 11g defining the spacing between each wire element. More or less grooves 10g and 11g may be incorporated in the rods 10 and 11, and it is not necessary that each groove or notch have a wire therein or that the rods 10 and 11 have an equal number of grooves. For parallel line or dot printing the wires pass through aligned corresponding grooves in each rod, respectively, so that the wires are essentially parallel. It is to be understood that this parallelness of the wires is only necessary where it is desired that the final printed product have parallel lines. It may in some instances be desirable to have a different or non-parallel spacial orientation of the printed lines, for example converging to diverging, or, as described more fully hereinafter, to effect a different dot pattern. While both upper 18U and lower 18L reaches of wires 18 may be used to suspend printing media, a surface 108 (FIG. 2) of rod 10 and a corresponding surface of rod 11 extend below frame members 13.and 14 so that lower wire reaches 18L are more easily brought to printing media transfer relation with a substrate. Although not shown in the drawings, the frame members may engage stops or abutments spaced about the'substrate holder (FIG. to control or limit the spacing and/or pressure between the wires and the substrate being printed upon.

Moreover, it is not necessary that each groove or notch g and 11g have wires therein as the wires may be wound at any arbitrary distance or pitch between wires so, if desired, several printing operations may be made with intermediate lateral shifting or adjusting of the frame relative to the previously printed lines on the substrate to effect printing between the previously printed lines (as described more fully in relation to FIG. 5). Alternatively all of the grooves in the rods 10 and 11 may have a wire wound therein, the number of wires, spacing, etc., being selected as desired for a particular design. After the wires have been wound, screws 16 and 17 may be adjusted so as to adjust the tension in wires 18, it being obvious that because the wires may be l mil in diameter, or smaller, for example, that too much tension would break the wires. It is preferred that each wire has substantially the same tension as its neighboring wire although this is not a mandatory requirement. Moreover, although the wires are shown wound around both the upper and the undersides of the rods, e.g., upper and lower reaches 18U and 18L, this is not necessary inasmuch as the wires may simply extend between rods 10 and 11, being fastened at each end by clamps (not shown). Furthermore, pins (not shown)'corresponding to the groove or notch spacings may be wound with wires from one pin on one rod to a corresponding pin of the other rod. Moreover rods 10 and 11 need not be round and may be rotable in their respective mounting. I

This multiplicityof suspended parallel wires comprises the basic printing member or assembly which may be manually or mechanically translated for print ing operations. The printing media may be applied to the wires by spraying, dipping, transfer from a pallet to the wires by contact, or by attraction of particulate matter to electrically charged wires. Of course, care must be taken that capillary action does not cause printing media to fill the free space between adjacent wires. Thus, where lines or dots are to be printed with very small spacing between lines, it may be desirable to space wires 18 a multiple of the desired line spacing 4 and shift the substrate or frame and print one or more times between the previously printed lines.

The present invention discloses as one preferred method of applying printing media the contact of suspended wires 18 with the surface of a flat or planar printing media pallet 30 (FIG. 3) which has previously had the printing media uniformly applied thereto. The printing media layer on pallet 30 is of controlled thickness and viscosity. In a simple arrangement, after transfer of printing media to printing wire assembly 9 or 9A, pallet 30 may simply be replaced by the substrate to be printed upon and printing wire assembly 9 or 9A brought into printing media transfer relation with the surface of the substrate where by contact or otherwise, wetting and ink transfer is effected.

It is frequently desirable to produce very small dots, for example adhesive dots, having a diameter of 2 mils or less which dots must be accurately registered and printed on a given substrate surface. For example, if it is desired to apply a plurality of small glass spheres (FIG. 7) having diameters between 3 to 10 mils or larger in accurately registered patterns between lines 101, or oriented patterns, on a surface 102 of a glass coating 103 overlying lines 101, adhesive dots 104 may be printed on the substrate surface 102 using the process and apparatus of this invention and then the glass spheres 100 may be cascaded across the surface 102 and because of the small size of adhesive dots 104, only one glass sphere 100 may be attached to each dot 104. In this case the printing media is an adhesive. Accordingly, the invention contemplates the printing of small dots in regularly oriented arrays or patterns and for this purpose, attention is invited to FIGS. 3 and 4 of the drawings.

In FIGS. 3 and 4, 40 designates a printing media or wire inking station, 41 designates a first wire set and operating mechanism, 42 designates the actual dot forming station, 43 designates a second wire set with the wires oriented transversely (preferably orthogonally) to the first wire set and its operating mechanism and'44 designates the actual printing station where the substrate upon which the dots are to be placed is located in substrate holder.

It is apparent that for purposes of this invention specific structural details are not necessary or important for an understanding of the invention and hence for purposes of clarity have been omitted from the drawmgs.

Printing media station 40 includes printing media pallet 30 which has a layer of printing media (not shown) uniformly applied thereto. First wire assembly and operating mechanism 41 includes printing wire assembly 9A and a translating or operating mechanism which includes a pair of wire assembly translating arms 51 and 52 secured at their ends 53 and 54, respectively, to shaft 56 which, in turn, is journaled in bearings 57 and 58. The opposite ends 59 and 60 of arms 51 and 52 have, a subframe 61 supported thereby on which wire assembly 9A is supported, it being appreciated that subframe 61 may be eliminated and wire frame 9A secured directly to ends 59 and 60 of arms 51 and 52, respectively. The assembly is translated by rotating shaft 56 through an angle of about more or less. To this end, gear 62 is splined on shaft 56 and meshed with a rack 63 which is translated along a linear path (indicated by the arrow 64) by an actuating arm or rod 66. Actuating arm 66 is connected to a source of power as for example a fluid or electric motor (not shown) such motor being actuated in a timed sequence in connection with the actuation of the operating mechanism for the second wire assembly 9B. The 180 (more or less) rotation of shaft 56 translates wire assembly 9A from the printing media station 40 where the wires have received or picked-up printing media on the lower reaches 18L of wires 18 so that when translated to dot forming station 42, the lower reaches 18L of wires 18 on wire assembly 9A are facing upwardly in a position to transfer printing media to wires 18 on wire frame assembly 98.

Wire frame assembly 98 is mounted on subframe 71 which, in turn, is journaled for rotation in bearing assemblies 72 and 73 at the ends of translating arms 74 and 76 respectively. The opposite ends of arms 74 and 76 are secured to actuating shaft 77 which, in turn, is journaled for rotation in bearings 78. and 79. Wire frame assembly rotating belt 80 is trained about fixed pulley 81 and about pulley 83 which is secured to a stub extension of the mounting shaft 84 for wire frame assembly 9B. Rotary translation of wire frame assembly 9B from the dot forming station 42 to the position illustrated in FIG. 3 is accomplished by a gear 86 splined to shaft 77, and gear 86 is meshed with reciprocating rack 88 which is reciprocated by means of operating shaft connection 89 to fluid or electric motor means (not shown) or other operating means.

The timing sequence and direction operation of the racks 88 and 63 may be accomplished by cams (on shaft 77 and 56) details of such timing sequence not being pertinent to the invention claimed herein. It is only necessary that wire frame assembly 98 be in a position to permit wire frame assembly 9A to be translated from a printing media receiving station 40 to the dot forming station 42 (FIG. 4) and to permit wire frame assembly 9B to travel from the printing station 44 (or some intermediate position) about an arc with the attendant rotation of wire frame assembly 9B about the axis thereof on arms 74 and 76 to the position shown in FIG. 4 and further movement to contact wire frame assembly 9A and effect transfer of printing media from wires on wire assembly 9A to wires on wire assembly on 9B only at the crossing points of such wires. (In FIG. 4 wire assembly 9B is shown in the process of being translated to dot forming station 42). Thus, with wire assembly 9B having the wires thereon oriented in a direction of 90 (other angles being contemplated herein) with respect to the directional orientation of wires in wire assembly 9A, the transfer of material to the wires on wire assembly 9B occurs only at the 90 intersections of the two wire assemblies, and the second wire assembly 9B now defines the dot pattern which can be printed upon a flat surface (or not so flat surface with the aid of an electrical field assist not shown).

It will be noted that the wires on wire assembly 98, which then have the material transferred thereto at the above wire crossing or intersections may simply be linearly raised, laterally translated and then lowered directly to print upon a substrate surface. However, in the disclosed embodiment, for purposes of simplicity, wire frame assembly 9B is simply translated to printing station 43 (FIG. 3) by the approximately 180 movement of arms 74 and 76. This movement is accomplished through the belt and pulley assembly 80, 81 and 83, it being obvious that more or less degrees of turning of wire frame assembly 9B may be accomplished by varying the relative ratios of diameters of pulleys 91 and 83, for example for effecting any desired degree of rotary movement of either the wire frame assembly or support thereof.

Substrate holder or printing station 44 (shown in FIG. 5) comprises a base having a flat upper surface 91 and an end member 92 projecting above the level of surface 91. A substrate holding subframe 93 is positioned on the surface 91 and has a lower projection 94 through which passes a coupling link 95 to lock assembly 96 mounted on the outside wall of member 92. A shim or spacer member 97 of calibrated thickness is positioned between the outer wall surface of projection 94 and the inner wall surface of end member 92. Actuation of lock assembly 96 by operating handle 98 draws the outer edge of member 94 into snug fitting abutment with spacer shim 97 to thereby clamp the subframe 93 in a fixed position.

Subframe 93 has a shallow recess in the upper surface thereof which receives substrate 99. Adjusting screws 111 may be adjusted to provide for a lateral adjustment of substrate 99 in substrate subframe 93. Calibrated adjustments of substrate may be effected by releasing lock assembly 96 and replacing shim 97 with a shim having a different calibrated width. However, the invention contemplates other forms of adjustment mechanisms. While substrate holder 44 has been described in connection with holding and adjusting a rigid plate like substrate, such as one-fourth inch thick glass panel, it will be appreciated that the substrate may be flexible. Moreover the adjustment of the printing locations on the substrate may be adjusted by adjustments of the wire frame assembly relative to the substrate holder or, in some cases, it may be desirable to provide for adjustment of the substrate as well adjustment of the wire frame assembly. It is obvious that the adjustments may be rotary and angular as well as linear. In FIG. 5, wires 18L, shown greatly enlarged in relation to the substrate, are shown in position for transferring printing media to the substrate.

It will be appreciated in FIG. 3 that the first assembly and operating mechanism 41 may be disabled and the pallet 30 positioned at station 42 in which case straight lines will be printed'on the substrate instead of dots. Whether dots or lines are being printed or a combination of dots and lines, the positioning of same may be effected by adjustment of the position of the substrate 99 as described earlier herein.

With reference to FIGS. 3 and 4, the position of printing station 44 and printing media station 40 may be reversed with an attendant reversal of the functions of wire assembly and operating mechanisms 41 and 43. In which case, the-timing may be such that wire assembly 9B is positioned at dot forming station 42 with printing media on the wires and then wire assembly 9A translated to pick up printing media in a dot pattern for application to a substrate. Other variations in this sequence are within the scope of the invention.

Although preferable, it is not necessary that adjacent wires of a wire assembly be of equal diameter. It may be desirable to print alternate wide and narrow lines large or small dots, in which case alternate wires could be of a larger diameter. For example, alternate 1 mil and 2 mil wire may be suspended between rods 10 and 11 and clamped in place. The spacing between wires may be uniform or nonuniform. Various combinations of line and dot patterns on the same surface are possible, and dots and dot patterns on the same surface are possible, and dots having a dimension larger than line widths may be printed directly on the lines to bridge two or more adjacent lines to form, for example, various circuit connections for making printed circuit boards. Although the substrates to be printed upon by the wire assembly are generally planar, it is contemplated that curved surfaces, particularly convex surfaces, may be printed upon directly by the wires. Concave surfaces may be printed by wire printing line and/or dot patterns directly upon a complementary convex surface and using such complementary convex surface as a printing member or carrier for printing on the concave surface. In this way, color phosphors may be applied to color television screens for example.

It is not necessary that the surface be perfectly flat since as described above, when printing lines, on contact of a segment of the wire to a part of the substrate, capillary forces between the substrate to be printed and the media on the wire tend to draw the entire coated length of the coated wire into position at the substrate surface. Hence, it is to be understood that the tension or the use of the term taut-wire is to be understood in this context that the tension is sufficient to maintain the wires straight to effect the distortionless printing desired herein.

FIGS. 6 and 7 illustrate two products printed in accordance with the invention herein. FIG. 6 illustrates a flat glass substrate 99 which has had printed thereon conductive lines 101. Conductive lines 101 may, for example, have a spacing of 25 mils between centers with the line widths being between 2 and mils. The product shown in FIG. 7 is comprised of the product illustrated in FIG. 6 except that a thin uniform layer of dielectric, such as glass has been applied over the surface and conductors of substrate 99. In this instance, the surface 102 of the dielectric coating 103 has adhesive dots 104 printed between conductor lines 101. Using I mils size wires, these adhesive dots have a lateral dimension of about 1 mil and may be positioned between conductor lines 101 by the lateral adjustments in the substrate holder or wire frame assemblies as described earlier herein.

Thus, adhesive dots 104 may be positioned in any desired pattern between or even over on conductor 101. After the adhesive dots 104 have been applied in any desired pattern, small spheres 100, such as glass beads, having diameters substantially larger than the dimensions of adhesive dots 104, are cascaded over surface 102. In this way, because of the very small size of the adhesive dots, and because the spheres, e.g., glass beads, are substantially larger (3 to 10 mils) than the adhesive dots, only one sphere can touch a dot at a time which permits placing of these spheres on the surface 102 by simply cascading the spheres over the adhesive dot printed surface. This technique of placing small spherical objects at predetermined locations on a surface has been used to place 6, 8 and 10 mil diameter glass spheres on glass surfaces. Such glass spheres or beads have been placed at 1600 per square inch, 100 per square inch, 16 per square inch and in several different row and/or pattern configurations, the variety of dot patterns and configurations being variable as desired to accommodate any requirement. Instead of cascading spheres, it will be obvious that other geometric regular or irregular bodies or substances may be cascaded across the surface 102 and such that the bodies adhere at the points of adhesive dots. Methods other than cascading can be used. Likewise, the bodies or 8 substances may be materials other than glass, e.g., metals, phosphors, and/or phosphor loaded organic resins.

The adhesive may be pyrolyzable (in the art pyrolyzable sometimes means that the material will combust completely and leave little or no residue). As used herein, it also means that the fugative material (a polymer), upon heating at a suitable temperature, converts to small volatile molecules, such as the monomeric form, which are then conveniently removed. The adhesive, for example, may be removed by pyrolization and then the assembly with the glass sphere thereon fired at a temperature to soften the surface 102 and at the same time pyrolyze adhesive dot 104 and permit glass sphere to fuse to the surface 102.

In practicing the aforementioned line printing embodiment(s) of FIGS. 1 to 3, a single strand of 1 mil diameter stainless steel wire was inked by suspending the wire by its ends and allowing the major segment of the length of the wire to rest on a thin layer of gold resinate printing media which had been applied to a flat glass plate which served as a printing media pallet. Then, the wire was removed from the pallet surface and placed onto a clean glass surface. When the wire was removed from this surface an amount of the gold resinate had been transferred. This simple model provides an explanation to the successful printing of very thin lines with wires. Printing and firing (PAF) inks are generally characterized as being pastes. They are relatively viscous and adhere well to glassy and metal surfaces and to the surface of most plastics (nylon, polyethylene, etc.). If the inked, flat substrate (the pallet) is uniformly coated with a thin layer (range from A to 20 mil) of PAF material, the wire will be coated uniformly along its leading surface and when removed from the pallet, will (via ink splitting) retain a uniform distribution of ink over the hemicylindrical surface of the wire. On contact of a segment of the wire to a part of the substrate, capillary forces between the substrate to be printed and the ink on the wire tend to draw the entire length of the coated wire into position at the substrate surface. At this point in the printing cycle, the ink, if it has undergone distortion due to action of ink splitting, droplet formation, poor wetting characteristics between wire and ink and the like, tends to recover uniform distribution along the wire-substrate interfaces.

The PAF materials which have been used to taut-wire print lines were obtained from l-Ianovia Gold Division of Englehard, Ind., DuPont de Nemours Co., Electro Science and Metals Unlimited, Inc. These materials may be used as received" from the manufacturer; however, they may also be altered to provide improved printing characteristics. For example, as received PAF materials tend to dry quickly and alter viscosity and composition over a time lapse on the order of 5 to 10 minutes. Another problem arises where the as received material is not sufficiently dense in metal content to provide an electrically continuous conductor after the firing process or the conductor element may be insufficiently conductive. One method of improving these materials has been to remove the liquid fraction through centrifugation and to reconstitute the material with an extremely low volatility fugative material such as poly(alpha-methylstyrene). Another alternate procedure is to reconstitute the centrifuged material with a metal resinate so as to increase effective metal density of the oven fired material.

The following is a list of conductive and non-conductive wires or monofilaments which have been used to taut-wire print:

1 mil diameter 3 mil diameter 1%. l. and 2 mil diameter 1.5 mil diameter 1.7 and 6 mil diameter Platinum-tungsten wire* Copper wire Stainless Steel wire Nickel wire Nylon monofilament I. Z and 3 were obtained from Consolidated Reactive Metals. Inc.

Mamoroncck. New York.

was obtained from Sigmond Cohn Corp.. Mt. Vernon. New York.

5 was obtained from Celenese Division of Monsanto, Cleveland. Ohio.

portant to the method of printing and to the results. In

The nature of the wire or monofilament may be imsome cases the nylon seems more compatible with PAP material used and in other cases the wire seems to provide a more uniform distribution of ink.

electric field assist can be and has been used to provide The use of conductive wires has an advantage in that the taut wire(s) against the surface of the substrate in a relatively snug position such that the wire(s) conforms to the contour of the surface.

have been taut-wire printed'on glass substrates:

and of conductivity of the lines after oven firing. Line widths were from 3-4 mils.

The following is a list of PAF type materials which Gold Paste VOIF Gold Paste A1560 Gold Resinate 9646 Tantalum Resinate 7522 Silver Resinate 9144 Nickel Resinate 58A Platinum Paste 6923 Silver Paste 5630 Silver Paste 7095-v Silver Paste 7313 Silver Paste 7522 Silver Paste 8032 Silver Paste 77l3 Hanovia 'Electro Science Silver Paste 590 Metals Unlimited Gold Paste C5004 Gold Paste C5005 Gold Paste C501 1 Conductivity Measurements and Electrode Configurations Measurements of physical and electrical continuity Material Conductivity /in.

A1560 gold "as received 7713 and 9144 Ag Paste and A Resinate 7%13 Ag as received" 590 Ag paste VOIF modified In the practice of this invention substrates have been prepared with 40 continuous parallel lines to the inch over the entire surface of a 5 X 6% (inches) flat glass plate. Likewise, substrates have been prepared with 80 continuous parallel lines to the inch with each line being about 2 mils wide. Line pairs have also been prepared with the gaps between each member of a pair ranging from about I to 10 mils.

Widths and diameters (of lines and dots) varying from 1 to 10 mils have been printed in the practice of this invention by using different monofilament diameters. Likewise, the width or diameter can be varied by altering the printing media and by controlling the amount of time used to apply the printing media to the wire and the time used in transferring the media to the substrate, e.g., the time during which the wire(s) is in the printing transfer relation. Likewise, the quantity of printing media used to print the line or dot, e.g., the total volume of media transferred, can be controlled via the foregoing variables. Typically the line width or dot diameter will be approximately equal to or slightly greater than the diameter of the wire.

Although what has been described herein is the bringing of wire assembly 9 carrying the printing media from above downwardly to the substrate to be printed, it will be understood that in some cases it may be preferred to hold wire assembly 9 stationary, apply printing media having a relatively low viscosity to wires 18 and then bring the substrate from above into printing media transfer relation with the wires. In this way the force of gravity is acting on the printing media away from the surface being printed upon, which, for some applications, tends to avoid droplet formation on the printing side of the wires and aids in achieving line uniformity. It will also be understood that the printed substrate may serve as an intermediate printing member or carrier and printing media on such intermediate member may be subsequently applied in the same pattern to a final printing surface. Likewise, in the dot printing embodiment, lines may first be printed on an intermediate substrate and thereafter a transversely oriented wire brought into contact with such substrate to effect transfer of printing media at the area of crossing. The dot containing wire(s) may then be brought into a printing media transfer relationship with a second substrate.

Although this invention has been described with reference to the printing of continuous electrode lines, it also may be used to prepare discontinuous electrode lines, e.g., by means of a sectioned or digitalized pallet. In addition this invention may be used to prepare lines or dots of different or varying diameters; e.g., by means of wires having irregular or regular variation in the surface, width, and/or diameter thereof.

Although the invention as described hereinbefore may be used to apply printing media to any suitable substrate, it is especially useful for printing on a rigid substrate particularly a printing media impervious substrate.

While the invention has been described and illustrated with reference to a limited number of specific embodiments and/or applications, it is to be understood that the invention is capable of various other modifications not departing from the essential spirit thereof which will become apparent to those skilled in the art.

I claim:

1. A method of forming a pattern of dots on a substrate comprising the steps of, supplying at least one elongated member with a printing media extending along its length, placing the said member into transverse and printing media transfer relationship with a plurality of coplanar members to transfer a portion of said printing media from said first member to said co: planar members, and then bringing said coplanarmem- 1 1 bers into printing media transfer relationship with a substrate to transfer a pattern of dots thereto.

2. Printing apparatus comprising, in combination, an assembly of a plurality of flexible wires supported in tension in non-crossing relation between a pair of spaced apart members, a printing media applying station, and means for translating said assembly of wires to said printing media applying station to transfer printing media to said wires and then to printing media transfer relation with respect to a substrate to transfer printing media to said substrate in a pattern determined by said assembly of wires, said printing media applying station including a second assembly of a plurality of small gauge flexible wires supported in tension in non-crossing relation between a further pair of spaced apart members, said further pair of members and the wires supported thereby being transversely oriented with respect to said first pair of spaced apart members and the first mentioned assembly of a plurality of wires at the time of transfer of printing media between said first mentioned assembly of a plurality of wires and said second assembly of a plurality of wires.

3. Printing apparatus as defined in claim 2, including means for applying printing media to said second assembly of small gauge flexible wires.

4. Printing apparatus as defined in claim 3, wherein said means for applying printing media to said second assembly of small gauge flexible wires includes a substantially flat printing media bearing platen,

and further means for translating said second assembly of small gauge flexible wires to printing media transfer relation with said printing media bearing platen and then to a position for transfer of printing media to said first wire assembly in a pattern of dots determined by the spacing and angular orientation of the wires of said wire assemblies when in juxtaposition with one another.

5. A printing process for printing patterns on a substantially flat planar substrate surface comprising the steps of; arranging a set of co-planar wires extending in a free space region between two spaced wire support members with the wires being unsupported intermediate said support members; applying a printing media to said set of co-planar wires in said free space region, and then bringing said wires in said free space region and said flat planar substrate to be printed upon into printing media transfer relation to simultaneously transfer a portion of said printing media from all of said wires in said set of coplanar wires to the surface of said substrate in a pattern defined by said wires, and then moving said wires and substrate out of said printing media transfer relation, and wherein in bringing said wires and substrate into and out of said printing media transfer relation one of said substrate and set of wires is moved at an angle to the plane of the other,

and wherein said pattern defined by said wires is constituted by a series of straight lines corresponding in number to the number of wires in a set, including positioning a plurality of small dots of printing media in a selected pattern on said substrate comprising the steps of,

arranging a second set of wires in free space between a second pair of spaced points,

applying printing media to said second of wires, from a transversely oriented set of wires to form said selected pattern of dots on said second set of wires, and

transferring said selected pattern of dots to said substrate.

6. Printing apparatus comprising a plurality of free space suspended coplanar taut-wires, holding means holding said wires in taut coplanar condition and with intermediate portions of the wires being unsupported, means for applying printing media to said intermediate portions of said wires, and means for simultaneously bringing all of said plurality of suspended taut wires as a unit into printing media transfer relation with a printing media receiving substrate to simultaneously transfer printing media from all of said wires to said substrate in a pattern determined by said plurality of free space suspended co-planar taut-wires, and means for relatively moving all of said wires as a unit and the substrate away from each other in a direction extending at an angle to the plane of said wires,

a second plurality of free space suspended coplanar taut-wires constituting said printing media receiving substrate,

said second plurality of wires being transversely oriented with respect to the directional orientation of the first mentioned plurality of wires whereby printing media on said first mentioned plurality of wires is transferred to said second plurality of wires only at their points of crossing,

and means for bringing said second plurality of wires into printing media transfer relation with a second printing media receiving substrate to transfer printing media to said second substrate in the pattern of said media on said second plurality of wires. 

1. A method of forming a pattern of dots on a substrate comprising the steps of, supplying at least one elongated member with a printing media extending along its length, placing the said member into transverse and printing media transfer relationship with a plurality of coplanar members to transfer a portion of said printing media from said first member to said coplanar members, and then bringing said coplanar members into printing media transfer relationship with a substrate to transfer a pattern of dots thereto.
 2. Printing apparatus comprising, in combination, an assembly of a plurality of flexible wires supported in tension in non-crossing relation between a pair of spaced apart members, a printing media applying station, and means for translating said assembly of wires to said printing media applying station to transfer printing media to said wires and then to printing media transfer relation with respect to a substrate to transfer printing media to said substrate in a pattern determined by said assembly of wires, said printing media applying station including a second assembly of a plurality of small gauge flexible wires supported in tension in non-crossing relation between a further pair of spaced apart members, said further pair of members and the wires supported thereby being transversely oriented with respect to said first pair of spaced apart members and the first mentioned assembly of a plurality of wires at the time of transfer of printing media between said first mentioned assembly of a plurality of wires and said second assembly of a plurality of wires.
 3. Printing apparatus as defined in claim 2, including means for applying printing media to said second assembly of small gauge flexible wires.
 4. Printing apparatus as defined in claim 3, wherein said means for applying printing media to said second assembly of small gauge flexible wires includes a substantially flat printing media bearing platen, and further means for translating said second assembly of small gauge flexible wires to printing media transfer relation with said printing media bearing platen and then to a position for transfer of printing media to said first wire assembly in a pattern of dots determined by the spacing and angular orientation of the wires of said wire assemblies when in juxtaposition with one another.
 5. A printing process for printing patterns on a substantially flat planar substrate surface comprising the steps of; arranging a set of co-planar wires extending in a free space region between two spaced wire support members with the wires being unsupported intermediate said support members; applying a printing media to said set of co-planar wires in said free space region, and then bringing said wires in said free space region and said flat planar substrate to be printed upon into printing media transfer relation to simultaneously transfer a portion of said printing media from all of said wires in said set of coplanar wires to the surface of said substrate in a pattern defined by said wires, and then moving said wires and substrate out of said printing media transfer relation, and wherein in bringing said wires and substrate into and out of said printing media transfer relation one of said substrate and set of wires is moved at an angle to the plane of the other, and wherein said pattern defined by said wires is constituted by a series of straight lines corresponding in number to the number of wires in a set, including positioning a plurality of small dots of printing media in a selected pattern on said substrate comprising the steps of, arranging a second set of wires in free space between a second pair of spaced points, applying printing media to said second of wires, from a transversely oriented set of wires to form said selected pattern of dots on said second set of wires, and transferring said selected pattern of dots to said substrate.
 6. Printing apparatus comprising a plurality of free space suspended coplanar taut-wires, holding means holding said wires in taut coplanar condition and with intermediate portions of the wires being unsupported, means for applying printing media to said intermediate portions of said wires, and means for simultaneously bringing all of said plurality of suspended taut wires as a unit into printing media transfer relation with a printing media receiving substrate to simultaneously transfer printing media from all of said wires to said substrate in a pattern determined by said plurality of free space suspended co-planar taut-wires, and means for relatively moving all of said wires as a unit and the substrate away from each other in a direction extending at an angle to the plane of said wires, a second plurality of free space suspended coplanar taut-wires constituting said printing media receiving substrate, said second plurality of wires being transversely oriented with respect to the directional orientation of the first mentioned plurality of wires whereby printing media on said first mentioned plurality of wires is transferred to said second plurality of wires only at their points of crossing, and means for bringing said second plurality of wires into printing media transfer relation with a second printing media receiving substrate to transfer printing media to said second substrate in the pattern of said media on said second plurality of wires. 